Seminario: Darius Modirrousta Galian (UNIPA), 12 Febbraio 2020 ore 15:00 Aula OAPA

In this paper we propose an analytic function for the bond albedo of an airless or near-airless magma ocean planet (AMOP). We generated multiple 100 m wide 1D fractal surfaces unto which we individually bombarded 10,000 light rays. Using an approximate form of the Fresnel equations we measured how much of the incident light was reflected. Having repeated this algorithm on varying surface roughnesses we find the albedo as a function of the Hurst exponent, the geochemical composition of the magma, and the wavelength. As a proof of concept, we used our model on Kepler-10 b to demonstrate the applicability of our equations. We present the albedos of different lava compositions and multiple tests that can be applied to observational data in order to determine the characteristics of the lava. When applied to Kepler-10 b we show that the high albedo could be caused by a moderately wavy ocean composed of oxidised metallic species such as FeO, Fe2O3, Fe3O4, and some silicates. This would imply that Kepler-10 b is a coreless or near-coreless body. However, since the uncertainty in albedo measurements is large there is a strong degeneracy in the surface composition.